The imam completing the prayer after remembering that he was not in a state of ritual purity

The questioner:
Honorable Shaykh, may Allah grant you success, I am the imam of a mosque. I entered one of the prayers without having performed the ablution for prayer, forgetting it, and I did not remember until the second rak'ah. It was a prayer recited aloud, so I completed the prayer because I knew that those behind me would not step forward to lead the prayer if I were to appoint one of them. I am.

The Shaykh:
Yes.

The questioner:
If I did this and completed the prayer to avoid causing disturbance to the worshippers, is my action valid?

The Shaykh:
No, this prayer is invalid. It is not permissible for you to wait if you know of anything, nor to complete the prayer in that state. However, if you are next to one of the known [capable worshippers], you may complete the prayer, and there is no harm according to a group of scholars. If you are next to one [who can lead], you pray and complete the prayer, and by Allah, their prayer is valid according to the fourth opinion of the scholars. But if you completed it yourself while you were not in a state of ritual purity, your prayer is invalid. You must repeat it. Their prayer is also invalid, because the invalidity of the ma'mum's prayer is due to the invalidity of the imam's prayer. You made a mistake in this.